The use of domestic flush toilets of the usual type having a hinged seat and lid is known to frequently lead to considerable domestic tension. This arises from biological differences between male and female, and differing customary habits arising therefrom.
Males customarily urinate from a standing position, whereas females normally sit. Accordingly, for sanitary reasons, and possibly as compensation for a poor aim, most men raise the seat of the toilet before urinating; and frequently forget, or are even in the habit of not relowering the seat thereafter.
This omission can lead to distinct hardship, in the event that a female sits upon the unprotected, cold, hard and possibly damp porcelain rim of the toilet, while there is considerable shock and stress in being suddenly unsupported when at the expected end of an habitual seating movement.
The shock effect can even be damaging in cases where any involved joint or muscle group, such as the hips, knees, or lower back are less than healthy, as in the case of an arthritic.
Earlier efforts to remedy this situation have included the provision of automatic seat positioning systems, as disclosed in U.S. Pat. Nos. 3,781,924; 4,291,422; 4,551,866, and 5,060,318 which utilize pneumatics, hydraulic cylinders and torsion springs, in addition to Guerty's No. 5,193,230, Mar. 16 1993, which uses a specialty hydraulic motor. Guerty's motor provides a high torque, elongated vane, oscillating motor, powered by water from the mains, to drive the seat to a lowered position. The special purpose motor has an eccentric rotor with a leaky vane, to permit manual repositioning of the attached seat, by leakage of water around the edge of the moveable vane.
The Guerty motor is expensive to construct, and requires careful sealing, being maintained at mains pressure all the time, at least up to the water admission control valve. In addition, the Guerty apparatus requires the provision of an ancillary piston chamber and piston, to push the seat from off its retracted, top dead centre position to an inclined position where a component of weight of the seat can become effective in its lowering operation.
The Guerty apparatus is expensive to manufacture, may require adjustment of its adjustable flow control jets, and may be subject to blockage and malfunction where the mains water contains salts or other precipitates that, over a period of time may foul the many flow passages, some of which are of restricted size. The use of hydraulic lock to control the rate of seat movement may also interfere with free repositioning movement of the seat when a number of males wish to make rapid sequential use of the flush, with the seat in a raised condition.